About MySQL development (Optimizer mainly)

Happy New Year to everyone! I published an article about row numbering and ranking with MySQL, here.

Colin, from Percona, wrote a nice post demonstrating a funny use of common table expressions: solving a Sudoku Puzzle . Ok, that's not the type of problem which matters a lot to database users... but it still feels good when he mentions that MySQL's implementation (which I wrote), is the fastest of all three tested DBMSs 😊.

Back from the PerconaLive conference! It was nice meeting some old faces 😃 There I presented MySQL's Common Table Expressions; check out my slides , with example queries and some details about the implementation. I got two suggestions from the audience: add to views the same single-materialization which we have in CTEs now (slides 19-27) support outer references in derived tables and CTEs. The first point would speed up queries which reference a view more than once. The second point would make it easier to write certain queries, where a subquery depends on the outer query's current row and this subquery contains a CTE. Will I get to work on any of these? Time will tell...

I published a new CTE blog here .

I did more CTE blogging: check it out here and here !

I realize that these last months I have not published anything... it's because I was quite busy developing a prominent feature: [Recursive] Common Table Expressions , also known as [recursive] CTE , [recursive] subquery factoring , WITH [RECURSIVE] clause. This feature is available today, in a Labs release of the MySQL Server. In my post here , you will find more information: syntax, capacities, examples... Feels good to have this big piece of work finally out!

Hello! I have posted this entry on the MySQL Server team's blog: Using the aggregate functions ANY, SOME, EVERY with MySQL   .